Regarding a technology of imaging a user's face, there are Patent Literatures 1 to 4.
The Patent Literature 1 describes a technology of analyzing eye position data and recognizing irises by using a camera configured to photograph a whole face and a moving camera configured to photograph an eye portion. The Patent Literature 2 describes a technology of photographing a face image, determining a face size, and zooming it at an appropriate field angle or view angle. The Patent Literature 3 describes a technology of changing a menu display of an electronic camera depending on the presence or absence of face recognition. The Patent Literature 4 describes a technology in which there are provided a face recognizing device and a device configured to detect a movement in a face area, and in which if there is a movement of a cosmetic tool or the like, the surroundings of a portion with the movement are enlarged and displayed.
Moreover, recently, with such imaging technologies as a background, there has been proposed a method of detecting the user's line-of-sight direction and using a detection result to improve safety during driving (e.g. refer to Patent Literatures 5 to 7). Moreover, there is also proposed an apparatus configured to use the detected line-of-sight direction to operate a personal computer, or the like. There are various methods of detecting the line-of-sight direction; for example, there are known a method of applying near infrared rays and using an image of a pupil of an eyeball and a Purkinje image, a method of measuring the line-of-sight direction from an eyeball central position obtained from an edge of the iris and a face position, and the like.
On the other hand, as a technology to which the user's image is applied, aside from the technology in which the line-of-sight direction is used, there is a technology in which the user's gesture is used. For example, there are an apparatus configured to use a gesture operation using a hand(s) so that a driver operates equipment (refer to Patent Literatures 8 and 9), an apparatus configured to use the gesture operation to operate a personal computer on a desk, or the like. For example, a virtual image display apparatus in the Patent Literature 8 is provided with: a viewpoint detection camera configured to photograph the driver's eyes; and a gesture detection camera to photograph the driver's hand(s). If the driver performs an operation of pointing at a displayed virtual image with his or her fingertip, image recognition processing is performed on images photographed by the viewpoint detection camera and the gesture detection camera. Then, the driver's eye position and fingertip position are detected, and the driver's line of sight is specified. The display of a gaze virtual image on the specified line of sight is controlled on the basis of a display control command.